### Off-Specular

Off-specular scattering from a monodisperse distribution of long boxes.

• The sample is made of very long boxes with length equal to $1000$ nm, width $20$ nm and height $10$ nm.
• The particles are distributed along a one-dimensional lattice with a lattice spacing of $100$ nm in the $x$-direction.
• The particles are rotated around the $z$-axis by $90^{\circ}$ so that their “infinite” dimension is parallel to the $y$-direction.
• The incident wavelength is equal to $1$ $\unicode{x212B}$.
• The output intensity is the result of an average over $\phi_i$ comprised between $-1^{\circ}$ and $1^{\circ}$ and of a scan of $\alpha_i$ and $\alpha_f$ between $0^{\circ}$ and $10^{\circ}$.

Note:

The two-dimensional output intensity is plotted as a function of $\alpha_i$ and $\alpha_f$.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77  """ Long boxes at 1D lattice, ba.OffSpecular simulation """ import bornagain as ba from bornagain import deg, angstrom, nm phi_f_min, phi_f_max = -1.0, 1.0 alpha_f_min, alpha_f_max = 0.0, 10.0 alpha_i_min, alpha_i_max = 0.0, 10.0 # incoming beam def get_sample(): """ Returns a sample with a grating on a substrate, modelled by infinitely long boxes forming a 1D lattice. """ # defining materials m_ambience = ba.HomogeneousMaterial("Air", 0.0, 0.0) m_substrate = ba.HomogeneousMaterial("Substrate", 6e-6, 2e-8) m_particle = ba.HomogeneousMaterial("Particle", 6e-4, 2e-8) # collection of particles lattice_length = 100.0*nm lattice_rotation_angle = 0.0*deg interference = ba.InterferenceFunction1DLattice( lattice_length, lattice_rotation_angle) pdf = ba.FTDecayFunction1DCauchy(1e+6) interference.setDecayFunction(pdf) box_ff = ba.FormFactorBox(1000*nm, 20*nm, 10.0*nm) box = ba.Particle(m_particle, box_ff) transform = ba.RotationZ(90.0*deg) particle_layout = ba.ParticleLayout() particle_layout.addParticle(box, 1.0, ba.kvector_t(0.0, 0.0, 0.0), transform) particle_layout.setInterferenceFunction(interference) # assembling the sample air_layer = ba.Layer(m_ambience) air_layer.addLayout(particle_layout) substrate_layer = ba.Layer(m_substrate) multi_layer = ba.MultiLayer() multi_layer.addLayer(air_layer) multi_layer.addLayer(substrate_layer) return multi_layer def get_simulation(): """ Returns an off-specular simulation with beam and detector defined. """ simulation = ba.OffSpecSimulation() simulation.setDetectorParameters(20, phi_f_min*deg, phi_f_max*deg, 200, alpha_f_min*deg, alpha_f_max*deg) # define the beam with alpha_i varied between alpha_i_min and alpha_i_max alpha_i_axis = ba.FixedBinAxis( "alpha_i", 200, alpha_i_min*deg, alpha_i_max*deg) simulation.setBeamParameters(1.0*angstrom, alpha_i_axis, 0.0*deg) simulation.setBeamIntensity(1e9) return simulation def run_simulation(): """ Runs simulation and returns intensity map. """ sample = get_sample() simulation = get_simulation() simulation.setSample(sample) simulation.runSimulation() return simulation.result() if __name__ == '__main__': result = run_simulation() ba.plot_simulation_result(result, intensity_min=1.0) 
OffSpecularSimulation.py